SpaceX F9 : RCM (RADARSAT) : Vandenberg : June 12, 2019 - DISCUSSION

[FlattestEarth]

If they decide not to land because of the seals, I'm going to predict that SpaceX will do another near-shore drone ship landing (between 25 and 40 kilometers downrange).

But rest assured, it'll still be spectacular, given that you can still see the booster land from a high hill.

Is there an advantage to that given they still have to tow it back to long beach?  At least at the cape they are closer to the port.

[ZachS09]

They can't land close to the Long Beach port because, as seen in this snapshot of Raul's SpaceX Map:

#1 - It wouldn't be safe for the booster to fly over the Channel Islands National Park to its ASDS location.

#2 - The Falcon 9 is travelling south-southwest, so that would mean that more fuel needed for the boostback burn.

Sorry for my sloppy drawing.

[FlattestEarth]

They can't land close to the Long Beach port because, as seen in this snapshot of Raul's SpaceX Map:

#1 - It wouldn't be safe for the booster to fly over the Channel Islands National Park to its ASDS location

#2 - The Falcon 9 is travelling south-southwest, so that would mean that more fuel needed for the boostback burn.

Sorry for my sloppy drawing.

So you're saying they will put the asds where your blue blob is?  Originally it sounded like you were suggesting a position where the landing would be visible from the launch site.

[ZachS09]

They can't land close to the Long Beach port because, as seen in this snapshot of Raul's SpaceX Map:

#1 - It wouldn't be safe for the booster to fly over the Channel Islands National Park to its ASDS location

#2 - The Falcon 9 is travelling south-southwest, so that would mean that more fuel needed for the boostback burn.

Sorry for my sloppy drawing.

So you're saying they will put the asds where your blue blob is?  Originally it sounded like you were suggesting a position where the landing would be visible from the launch site.

No. I was trying to make a point of why your opinion of landing close to the port would be a bad idea, hence why I drew the blue blob. I used the SSO-A drone ship location as an example of what to expect if RCM does a similar 3-burn trajectory.

I did the question mark as a way of saying, "Is it worth putting the drone ship there?"

[FlattestEarth]

Ok but draw a circle centered at the Port and with radius of sso-a distance.  What is the advantage of putting the asds near the launch site vs anywhere else within that circle?  If you can get any closer to the port and since you have plenty of fuel due to light payload.

[ZachS09]

Ok but draw a circle centered at the Port and with radius of sso-a distance.  What is the advantage of putting the asds near the launch site vs anywhere else within that circle?  If you can get any closer to the port and since you have plenty of fuel due to light payload.

It was my first time plotting predictions using Paint. No excuse.

[envy887]

Ok but draw a circle centered at the Port and with radius of sso-a distance.  What is the advantage of putting the asds near the launch site vs anywhere else within that circle?  If you can get any closer to the port and since you have plenty of fuel due to light payload.

Probably surface and airspace access restrictions and overflight rules? Maybe easier comms & telemetry downlink if it doesn't go under the horizon to the launch pad?

[crandles57]

So how far downrange is it at time of boostback burn? If it is further downrange, is it easier to change to a different ground track direction than it is to change to exactly the reverse of the ground track it was following? Seems like that might be less effort needed and maybe these issues need to be considered before deciding whether the blue blob position might be reasonable or not?

Tossing it just past directly vertical is one way to reverse the ground track direction and I think that is gernerally what they do. It may be possible to change the direction using a plane that is slanted to the vertical. Not sure if SpaceX has done this or if they might want to widen their experience.

[ZachS09]

Using the SSO-A mission as an example again, the Falcon 9 should be just left of San Miguel Island.

[envy887]

So how far downrange is it at time of boostback burn? If it is further downrange, is it easier to change to a different ground track direction than it is to change to exactly the reverse of the ground track it was following? Seems like that might be less effort needed and maybe these issues need to be considered before deciding whether the blue blob position might be reasonable or not?

Tossing it just past directly vertical is one way to reverse the ground track direction and I think that is gernerally what they do. It may be possible to change the direction using a plane that is slanted to the vertical. Not sure if SpaceX has done this or if they might want to widen their experience.

The booster has plenty of performance for a RTLS, so it's not really "easier" for a performance standpoint to to one or the other. Once it relights the engines for boostback, the only (small) difference is burn time. They are undoubtedly optimizing for something other than booster performance.

[FutureSpaceTourist]

https://twitter.com/canadainspace/status/1129438840828157952

Transporting the RADARSAT Constellation Mission to the Launch Site is Not as Easy as You Might Think  wp.me/p8gxCj-3ya #cdnspace #RCM #MDA #RADARSAT #RADARSATConstellationMission

[jacqmans]

An RCM spacecraft en route to Vandenberg Air Force Base

2019-04-24 – One of the RCM spacecraft leaves SSL in California, where it has been stored since October 2018, in preparation for launch from the Vandenberg Air Force Base. The RADARSAT Constellation is Canada’s new generation of Earth observation satellites. The three identical satellites work together to bring solutions to key challenges for Canadians. (Credit: MDA, a Maxar company)

[strawwalker]

I know there had been some question in the past as to whether the 1400 kg mass figure refers to a single sat or the three together. An infographic posted on CSA'a RADARSAT page a few days ago explicitly states "1430 kg each".

Text version:

The RADARSAT Constellation Mission (RCM) is Canada's new generation of Earth observation satellites. Three identical satellites work together to bring solutions to important challenges for Canadians. They monitor the environment, oceans and ice; detect ships; and support emergency teams during natural disasters. The satellites will be launched aboard a SpaceX Falcon 9 rocket in spring 2019. Approximately 250,000 images per year will be used, that is 50 times more than the first generation of RADARSAT. The bus (the body) of each satellite is 3.6 m high, about the height of two average men, by 1.1 m wide. The antenna is 6.98 m wide. The total mass of each of the three satellites at launch is 1,430 kg (approximately the weight of a black rhino). The RCM will orbit Earth at an altitude of 600 km. The satellites will move at 27,200 km/h and take about 96 minutes to circle the globe.

[gongora]

I know there had been some question in the past as to whether the 1400 kg mass figure refers to a single sat or the three together. An infographic posted ... a few days ago explicitly states "1430 kg each".

I knew that had to be the case but it's nice they finally said it outright.

[Alexphysics]

How much more mass could the deployer be? 1430kg x 3 = 4290kg so maybe total mass to orbit could be somewhere close to 5000kg? What do you think?

[smoliarm]

How much more mass could the deployer be? 1430kg x 3 = 4290kg so maybe total mass to orbit could be somewhere close to 5000kg? What do you think?

Yes, total mass to orbit of ~ 5000 kg sounds about right.

This flight seems to have plenty of extra performance:
NASA LSP calculator gives 8300 kg for Falcon 9 Full Thrust with RTLS for the orbit of 600 km at 98°.
Therefore, the dispenser can be even heavier than 700 kg - IF it is cheaper.

[sewebster]

Therefore, the dispenser can be even heavier than 700 kg - IF it is cheaper.

Ruag said the dispenser was the heaviest piece of hardware ever developed at their Linköping facility (see way upthread)... so it could be a heavy-ish dispenser.

[scr00chy]

Hmm, so is the static fire info incorrect, or is the launch date in the advisory outdated? Or did SpaceX manage to move the SF to the left?

[sewebster]

Hmm, so is the static fire info incorrect, or is the launch date in the advisory outdated? Or did SpaceX manage to move the SF left?

A bit of a mystery. Canadian side still seems to be working with June 11...

[Chris Bergin]

Hmm, so is the static fire info incorrect, or is the launch date in the advisory outdated? Or did SpaceX manage to move the SF to the left?

Moved to discussion as this above wasn't an update.

We still have the timeline as moved to the right to the dates we used.